It is known to the art to provide the nut of a ball nut and screw assembly with a wiper member having an inner helical thread that is received in the helical groove of the screw. The wiper is typically preloaded by a spring in a direction axially away from the nut end wall, causing the thread of the wiper to be forced axially in one direction against a portion of the side wall of the screw groove in order to minimize axial play or lash between the nut and screw. As the thread of the wiper traverses the screw groove during operation of the assembly, it has a tendency to completely wipe lubricant from this wall portion of the screw groove.
It is a principal object of the present invention to address the lubrication problem associated with the use of a preloaded wiper.